Excavator-tractor.



. 0. J. MARTINSON. IEXGAVATOR TRACTOR.

APPLICATION FILED APR. 6, 1913.

1,101,460. A Patented June 23, 1914.

Z-SHEETS-SHEET 1.

0. J. MARTINSON.

EXGAVATOR TRACTOR.-

APPLIOATION FILED APB..5, 1913.

1,101,460, Patented June 23, 1914.

2 SHEETS-SHEET 2.

llllllllllll l l l I l -'l UNITED STATES PATENT OFFICE.

OSCAR J. MARTIN'SON, OF CHICAGO, ILLINOIS, ASSIGNQB. 1'0 MONIG-HAN MACHINE 00.,

v A CORPGEATION OF ILLINOIS.

EXQAV ATOR-TRACTGB.

Specification of Letters Patent. Patented une 23, 1914,

Application filed April s, 1918. Serial No; 759,240.

To all whom it may concern:

Be it known that I, OSCAR J MAR'rmsoN, a citizen of the United States of America, and a resident of Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Excavator-Tractors, of which the following is a specification. v p

- This invention relates to mechanism for propelling heavy machinery, such as excavating machines and derricks, over rough or soft ground.

The main objects of the invention are to provide traction mechanism of this nature having many times the surface engagement with the ground "possible with wheels but operating on a similar principle; to provide traction mechanism including rotating wheel sectors and shoesor auxiliary bases for-said wheel sectors adapted to cooperate with a separate supporting base and having connections for being moved horizontally in the direction of travel of the machine while the weight of the machine is on said supporting base; to provide traction mechanism fOrheaVy-machinery with substantially flat shoes and means adapted to roll on said shoes to propel the machine-andtwhereby the 4 said shoes are provided with connections to the machine adapted to move the shoes 'horizontally over the surface of the ground while the said means are disengaged there-.

from. I

Further objects of the invention are to improve existing-mechanism of this nature adapted to propel heavy machinery by a walking or step by step movement by providing means for considerably increasing the amount of horizontal travel with respect to the up and down movements of the machines for each step taken. An illustrative embodiment of this 'invention is shown in theaccompanying drawings in which-- I Figure 1 is a side elevation of an excavating machine provided with traction mechanism showing the traction mechanism as it appears when in contact with the ground while propelling the machine. Fig. 2 is afragmentary side elevation showing the traction mechanism at rest in its normal position. Fig. 3 is a plan view of one of the wheel sectors and its 00- operating shoe or auxiliary base. Fig. 4 is a plan view of the device with some of the parts omitted.

The present invention is applicable to a wide variety of heavy portable machines or transporting devices, gun carriages, etc.-, for the purpose of propelling such devices over soft and uneven grou'nd surfaces. It is an improvement of excavating tractors shown and described in applicants copendin g" apl-ications for patent, Serial No. 756,473, ied March 24., 19;13,-and Serial No. 758,160, filed April 1, 1913. Each of said applications relates to an excavating mechanism rotatably mounted on a horizontally. disposed circular base together with rotating members and cooperating auxiliary bases adapted to propel such and similar machines forward by a step by step motion. Both of said applications for patent relate to propelling mechanism operating to propel their respective machines by step or are. movemen'ts around-some fixed point in contact with the ground. In the present case the machine -'is pro lled by giving it vertical movements com 'ined with a considerable extent of purely horizontal movement while its supporting wheel sectors roll on their respective shoes or auxiliary bases in contradistinc'tion to being fulcrumed thereon. In all of these diflerent types of propelling turntableof the machine may be permitted to drag-overthe earth at one side and thus assist an supporting steadying the machine while it is being propelled, or may be lifted entirely clear of the ground during such propelling movement. This depends upon the particular location of the propelling mechanism with respect to the centerfiof gravit of the. machine, or whether or not a plurality of such propelling mechanisms are Ifhe present device isalso distinguishable over prior devices in that the auxiliary bases or shoes are maintained a substantially horizontal position at all times and moved bot'li vertically and horizontally through connections with the coiiperatin wheel sectors. The present invention resu ts 'in a considerable decrease in the difiiculty and loss of time in the matter of transportin land dr'edges, steam shovels, and other similar mechanisms the main supporting base oremployed in-"connection with one machine.

machines in connection with theworking of said machines.

Referring to the drawings, the invention is shown byway of example, in combination with a land dredge of well known design. This dredge isrotatably mounted on a base or turntable 1 by a center bearing 2 and wheels 3 journaled on supports secured to the under side of a platform 4 and cooperating with a circular track 5 secured to base 1. The platform 4 supports the necessary motor or engine and machinery for dr1v1ng the operating mechanism .of the dredge. Said driving mechanism is, as usual, mclosed m a suitable housing 6. In Fi 1 a mast 7 is shown extending. upwardly t rough the roof of said housing and its upper end supports a sheave 8, the latter being part of a tackle for raising and lowering t e drag bucket supporting from a suitable controlling drum within the housing passes over the sheave 8 and a sheavell and again around sheave 8 having its ends secured to sheave 11. A link 12 connects sheave 11 with the end of, boom 9. At the end' of boom 9 there is secured a bucket hoisting line 13. This line passes around a sheave 14 on the bucket 15 and a sheave 16 on boom 9, and from there into the housing to its controlling power driven drum. The cable for dragging bucket 15 in its digging operation is designated by numeral 17. In the digging operation the necessary transverse swinging of boom 9 is accomplished by swinging the platform 4 and mechanism supported thereon around its bearing connection 2 with the base or turntable 1.

Suitable connections are provided for driving, as required, a shaft 18 journaled in bearings 43 on the platform 4. A clutch connection 35 whereby shaft 18 may be con nected to the operating motor 36 is shown in Fig. 4 of the drawings. This motor, as usual on this type of machine, has connections (not shown) for rotating the main body part of the machine upon its platform 1 as required in the operation of digging. By means of the clutch 35 the drive shaft 37 of the machine may be clutched to a beveled gear 38 journaled on the shaft and in mesh with a beveled gear 39 fast to a worm shaft 40. The latter carries a worm 41 meshing with a worm wheel 42 fast to shaft 181 The shaft 18 operates and su ports the traction mechanism to which t e present invention has direct relation. At each end of this shaft which overhangs the sides of the turntable 1 there is rigidly secured a cam 19, which may be in the form of a wheel or sector. The outer edge 20 of this cam is circular with respect to center of shaft 18 through the greater part of its length. But as this edge approaches the straight sides 21 of sectors 19 it is sloped boom 9. A boom line '10 leading inwardly toward shaft 18. The sectors 19 are designed'in this way in order that in operation when shaft 18 is rotating the corners 22 of the sectors by engagement with cooperating or auxiliary bases23 will, with an easy movement, first lift the entire machine, including base 1, more or less clear of the ground, and then cause the-machine to travel forward by the sectors rolling on said shoes 23. Then as the opposite corners 24 of the sectors arrive in the engaging position with shoes 23 the entire machine, together with its platform 1, is again gradually lowered into contact with the ground, platform 1 finally supporting the machine while the sectors 19 return to the position shown in Fig. 2, or again come into contact with the shoes '23 in the further operation of the traction mechanism.

The shoes or auxiliary bases 23 are hung from their respective wheel sectors 19 by cables 25. The latter are secured to eyes 26 in the corners of the shoes 23, and at their opposite ends are provided with hooks 27 by which they are secured'to horizontally disposed levers 28 having rings or eyes 29 for this purpose at their ends. The levers 28 are pivoted midway between their ends by pins or pivots 30 to the sectors 19. The pivots 30 are preferably located near to the outer edge 20 of the sectors 19 in order that upon rotation of the sectors the shoes 23 will be given the required horizontal movement with respect to the ground so as to provide for the relative rolling of sec tors 19 when the shoes are in contact with the ground. The cables 25 are preferably of such length that the auxiliary bases 23 will contact with the ground when pivot pins 30 are in the same horizontal plane with shaft 18. Thus the auxiliary bases are caused to make are shaped steps without any lost motion. If necessary the shoes 23 may be provided with teeth or shoulders 32 to prevent slipping between the sectors and their shoes, during the rolling action of the sectors when propelling the machine over the ground. During the lifting action of the sectors, previous to their engagement with shoulders 32, they slip with respect to the auxiliary bases 23, in this manner lifting vertlcally one end of the machine and its base clear of theground. Thewei'ght is.

preferably so distributed that the rear edge of the base remains in contact with the ground and assists in steadying and supporting the machine during its traveling movement over the ground.

In the operation of propelling a machine over the ground, rotation of the sectors 19- results in an' up and down movement of shoes 23 combined with a horizontal movement of the shoes. Lever 2 8 remainsin a substantially horizontal position during the operation, as its pivot 30 allows the sectors to rotate relatively of the levers 28. Startin Fig. 2, rotation of sectors 19 in the direction indicated by arrow 31 results; in pivot being carried forward of shaft 18 and thereby causing the shoes 23 to swing in a forward direction. I

ment of the sectors results in the shoes contacting with the ground in their forward position and the cables 25' becoming slack, so that the position of shoes 23 is not disturbed while sectors 19 are in contact therewith. When the sloping parts 22of the sectors are in contact with the shoes 23 one end of the machine and its support 1 are lifted more or less clear of the ground. During the lifting action of the sectors the latter slip with respect to the auxiliary bases lifting the machine vertically. In this manner the forward-end of the base is lifted outof any depression formed and into which the base may have sunk during the dredging operation. Then, when the surfaces 20 of the sectors cooperate with the Shoes 23 by rolling thereon, the entire machine will be carried. forward in a horizontal direction by the rolling of the sectors, the movement being transmitted from the sectors to the machine by causing horizontal bodily movement of shaft 18 in the required direction.

The continued rotation of the sectors results in permitting the machine and its turntable 1 to again gradually come to rest on the ground because of the inward slope of the parts 24 of thesurfaces .of sectors or cams 19. This operation, of course, may be continued if it is: desired. to cause the machine to move any great extent at one time, but in practice it is possible that the machinemay be moved only a short distance at each operation of the traction mechanism, and possibly between time intervals of considerable le gth.

It may happen that the machine is swung horizontally on its pivots a great many times during its work and between the operations of the traction mechanism, and at such times it may be desirable to detach the shoes 23 from the machine in order to avoid the needless swinging ofsaid shoes. It may be seenthat the hooks.27 will thus permit the machine to be swung independently of shoes 23.

In the peculiar operation ofthe present device, the machine is tilted to lift its forward end out of any depression which may have been formed in -the ground by the weight and vibration during work .of the machine. It also enables it to easily pass over normal obstructions in-its path. These machines have cases which afford consider- The continued moveing their operation of carried by said suction would require considerable the power, which in the present case may be devoted to urely tractlvev purposes.

It may be seen that this invention may be readily adapted to machines, not ,havin the turntable and will admit of such modification that b employing a plural ty of pairs of'sector wheels 19 wit corresponding shoes 23, itis possible to move the machine over the ground by a rolling action of the sectors on their shoes without giving the machine any up and down movement, except-Jaccording to the irregularities in the surface of the ground, as such pairs of sectors might be set at'diflerent relative angles on their respective shafts. Therefore while one'pair of sectors would be supporting and propelling the machine forward in a horizontal direction, other sectors could be performshifting in a horizon.- tal direction, or lifting and loweringtheir respective shoes 23. In this manner there would be substantially no up and down movement of the machine necessary except possibly a hardly noticeable movement when the weight of the machine is shifted from one pair of shoes to another.

Although but one specific embodiment of this invention has been herein shown and described, it will be understoodthat numerous details of the construction shown ma be altered or omitted without departing rom the spirit of this invention as defined by the following claims.

I claim I 1. In a machine of the class described, the combination of a base, a body rotatably mounted thereon, and propelling mechanism body and adapted to first lift the machine and then cause it to travel over the ground, said propelling mechanism comprising a wheel sectorand a cooperating auxiliary base carried by the wheel sector.

2. The combination with a body and a base therefor, of a wheel sector. 'rotatably connected to said body, a lever pivoted to said sector, an auxiliary base havin connections to said lever whereby sai lever and base remain substantially horizontal during rotation of the wheel sectorjbut are raised and lowered thereby and Said au'xil iary base is given a horizontal movement for the purpose of coijperating with said sector in moving the body over the ground.

3. The combination with a body and a base therefor, of a wheel sector .rotatably connected to said body, a leverpivoted to said sector, an auxiliary base having cono nections to said lever whereby said lever and base remain substantially horizontal durin rotation of the Wheel sector but are raise and lowered thereby and said auxiliary base is given a horizontal movement for the purpose of cocperating with said sector in moving'the machine over the ground, said connections permitting detachment of said auxiliary base from said wheel sector.

4:. The combination of operating mechanism, a base therefor, of a wheel sector rotatably connected to said operating mechanism, an auxiliary base cocperatlng with said wheel sector and connected therewith to be moved horizontally over-the ground, said auxiliary base being provided with a shoulder to limit slipping between said Tauxiliary base and said wheel sector.

5. In a machine of the class described, the combination of a supporting base having extended bearing area, a wheel sector rotatably mounted thereon and adapted to tilt said base and drag the same along the ground.

6. In a machine of the class described, the combination of a supporting base having extended bearing area, a rotatable member mounted thereon and adapted to first tilt said base and then drag the. same along the ground.

7. In a machine of the class described, the combination with asupporting base and body mounted on said base torotate in a horizontal plane, a wheel sector rotatably mounted on said body and adapted to lift the body and its base and propel the same over the ground, and an auxiliary base carried bysaid wheel sector and cocperating therewith for the purpose of supporting the machinewhile' it is beingpropelled. over the ground.

8. In a machine of the class described, the combination with a supporting base and bod mounted on said base to rotate in a horizontal plane, a wheel sector rotatabl mounted on said body and adapted to li t the body and its base and propel the same over the ground, and ried by said wheel sector and cocperating therewith for the purpose of supporting the machine while it is bemg propelled over the ground, said wheel sector being so formed as togradually lift the machine while slipping on said auxiliary base and then to propel the machine over the ground by rolling on said auxiliary base.

9. In a machine of the class described, the combination with a supporting base and body mounted on 'said base to rotate in a horizontal plane, a wheel sector rotatably mounted on said body and adapted to lift the body and its base and propel'the same over the ground, and an auxiliary base carried by said wheel sector and cocperating therewith for the purpose of supporting the machine while it is beingpropelled over the ground,

an auxiliary base carsaid wheel sector being so formed as to gradually lift the "machine while slipping on said auxiliary base and then to propel the machine over the ground by rolling on said auxiliary base and finally permitting the machine and its supporting base to gradually come to rest on the ground.

10. In a machine of the class described, the combination of a supporting base and body supported on said, base to rotate in a horizontal plane, a wheel sector rotatably mounted on said body and adapted to propel the said body and its supporting base over the ground, and an auxiliary base carried by said wheel sector, said wheel sector and auxiliary base cooperating to lift the machine before the propelling movement and to lower it after the propelling movement.

11. In a machine of the class described, the combination of a supporting base having extended bearing area, operating mechanism mounted thereon and adapted to first tilt said base and then drag the same along the ound.

12. In a machine of the class described, the combination of a supporting base having extended bearing area, operating mechanism mounted thereon and adapted to tilt said base and drag the same along the ground.

13. In a machine of the class described, the

combination of a supporting base having extended bear-ing area, and means rotatably mounted thereon and adapted to tilt said base and'drag the same along the ground.

14. In a machine of the class described, the combination of a base having extended hearing area, a body rotatably mounted thereon, and propellingmechanism carried on said body and ada ted to cause the machine to travel forwar while raising one side of said base from the ground and permitting the opposite side to "drag.

15. In a'machine of the class described, the combination of a base having extended bearing area, a body rotatably mounted on said base, and supporting a motor, and propelling mechanism driven by said motor and mounted on said body and adapted to cause the machine to travel forward while raising one side of the base and permittingthe opposite .side to drag over the earth and thereby steady the machine in its movement.

16. In a machine of the class described, the combination of a base having extended bearinlgl area, a body mounted to rotate horizonta mov able with said body and propelling mechanism actuated b said. shaft arrangedto lift one side of sai base while the opposite side is permitted to drag over the earth.

17. In a machine of the class described,'the combination of abase, a bod rotatably mounted thereon a horizontaly disposed shaft movable with said body, means for thereon, a horizontally disposed shaft" rotating said shaft, arms rigidly secured to drag over the earth when the machine is the ends of said shaft and supporting at being propelled. 13

each side of said body a foot at such dis- Signed at Chicago this 2nd day of April, tance from the shaft that when the latter is 1913.

i rotated the feet will engagethe ground, lift- OSCAR J. MARTINSON.

ing the machine and propelling it forward, Witnesses: the center of gravity of said machine being JOHN MONIGHAN,

so located that one side of said base will JENNIE BURT. 

